3,420 research outputs found
DPT Vaccine Controversy: An Assessment of the Liabilities of Manufacturers and Administering Physicians Under Several Legal Theories
From National Populism to National Corporatism: The Case of Bolivia (1952-1970)
Analyzes the experience of Bolivia with an experiment in a populist resolution of its socioeconomic problems from 1952 to 1970. Objectives of national populist ideology; Factors that lead to the failure of Movimiento Nacionalista Revolucionario in Bolivia to achieve its revolutionary goals: Resurgence of private sector in mining and petroleum
The Perspective from the Private Sector: The Institute for Tourism Development at the Rochester Institute of Technology
This article explores the development and organizational structure for a tourism center within a privately endowed university. The success of this undertaking has been directly related to the foresight of the administration and the cooperation among the faculty. Another important component of the success of this center has been private industry and their readiness to provide input, an well as dollars
Phonological priming effects on word retrieval and tip-of-the-tongue experiences in young and older adults.
A Human Torque Teno Virus Encodes a MicroRNA That Inhibits Interferon Signaling
Rodney P. Kincaid, James M. Burke, Jennifer C. Cox, Christopher S. Sullivan, The University of Texas at Austin, Molecular Genetics and Microbiology, Austin, Texas, United States of AmericaEthel-Michele de Villiers, Division for the Characterization of Tumorviruses, Deutsches Krebsforschungszentrum, Heidelberg, GermanyTorque teno viruses (TTVs) are a group of viruses with small, circular DNA genomes. Members of this family are thought to ubiquitously infect humans, although causal disease associations are currently lacking. At present, there is no understanding of how infection with this diverse group of viruses is so prevalent. Using a combined computational and synthetic approach, we predict and identify miRNA-coding regions in diverse human TTVs and provide evidence for TTV miRNA production in vivo. The TTV miRNAs are transcribed by RNA polymerase II, processed by Drosha and Dicer, and are active in RISC. A TTV mutant defective for miRNA production replicates as well as wild type virus genome; demonstrating that the TTV miRNA is dispensable for genome replication in a cell culture model. We demonstrate that a recombinant TTV genome is capable of expressing an exogenous miRNA, indicating the potential utility of TTV as a small RNA vector. Gene expression profiling of host cells identifies N-myc (and STAT) interactor (NMI) as a target of a TTV miRNA. NMI transcripts are directly regulated through a binding site in the 3′UTR. SiRNA knockdown of NMI contributes to a decreased response to interferon signaling. Consistent with this, we show that a TTV miRNA mediates a decreased response to IFN and increased cellular proliferation in the presence of IFN. Thus, we add Annelloviridae to the growing list of virus families that encode miRNAs, and suggest that miRNA-mediated immune evasion can contribute to the pervasiveness associated with some of these viruses.This work was supported by grants RO1AI077746 from the National Institutes of Health, RP110098 from the Cancer Prevention and Research Institute of Texas, a Burroughs Wellcome Investigators in Pathogenesis Award to CSS, a UT Austin Powers Graduate Fellowship to RPK, a UT Austin Institute for Cellular and Molecular Biology fellowship, and the DKFZ for EMdV. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Molecular BiosciencesMicrobiologyEmail: [email protected]
The Effects of Elevated Concentrations of Carbon Dioxide and Ozone on Potatoe (Solanum tuberosum L.) Yield
End of Project ReportPotatoes (Solanum tuberosum L. cv. Bintje) were grown in open top chambers at
Teagasc, Crops Research Centre, Oak Park, Carlow and exposed to ambient and
elevated concentrations of CO2 in combination with ambient and elevated
concentrations of O3 in the 1998 and 1999 growing seasons. Exposure to elevated
concentrations of O3 caused visual damage to the leaves of the potato plants in
both years of the study. In 1999, ozone damage to leaves was significantly reduced
in the presence of elevated concentrations of CO2. Stomatal conductance was
reduced by elevated CO2 and was reduced further by the elevated O3 treatment
under elevated CO2. Exposure to elevated CO2 increased tuber fresh weight yield
by 32% in both years of the study. The yield increase was attributable to larger
tuber sizes and not to an increase in the number of tubers. Tuber yield was
unaffected by elevated O3 at ambient concentrations of CO2 in both years of the
study. In 1999, the yield increase induced by elevated CO2 was substantially
reduced by the presence of elevated O3
Redox-mediated bypass of restriction point via skipping of G1pm
BACKGROUND: It is well known that cancer cells bypass the restriction point, R, and undergo uncontrolled cell proliferation. HYPOTHESIS AND EVIDENCE: We suggest here that fibrosarcoma cells enter G(1ps )directly from M, skipping G(1pm), hence bypassing R, in response to redox modulation. Evidence is presented from the published literature that demonstrate a shortening of the cycle period of transformed fibroblasts (SV-3T3) compared to the nontransformed 3T3 fibroblasts, corresponding to the duration of G(1pm )in the 3T3 fibroblasts. Evidence is also presented that demonstrate that redox modulation can induce the CUA-4 fibroblasts to bypass R, resulting in a cycle period closely corresponding to the cycle period of fibrosarcoma cells (HT1080). CONCLUSION: The evidence supports our hypothesis that a low internal redox potential can cause fibrosarcoma cells to skip the G(1pm )phase of the cell cycle
Clustering climate and management practices to define environmental challenges affecting gastrointestinal parasitism in Katahdin sheep
Gastrointestinal nematodes (GIN) negatively affect the performance and well-being of sheep. Due to anthelmintic resistance, GIN are difficult to control leading producers to choose breeds that can exhibit resistance to parasitism. An example is Katahdin sheep. Katahdins are raised in various climates and management systems in the United States. These environmental factors can be combined to form eco-management groupings or clusters. We hypothesized that GIN challenge varies predictably based on the characteristics of these environmental clusters. Forty Katahdin producers from across the United States were surveyed for management information, with body weights (BW), fecal egg counts (FEC), and FAMACHA scores (FAM) available from 17 of the 40 flocks. The performance data included 3,426 lambs evaluated around 90 d of age. Management and climate data were combined into clusters using multiple correspondence and principal component (PC) analysis. Performance data were aligned with their corresponding cluster. Depending on the trait, eco-management cluster, birth-rearing type, sex, and, as a covariate, dam age, were fitted as systematic effects with ANOVA. Clusters also were formed based on climate or management data alone. When compared with fitting the eco-management clusters, they defined less variation in each of the traits based on Akaike and Bayesian information criterion, and adjusted r2 values. To further examine variation defined by eco-management clusters, residuals from an ANOVA model excluding eco-management cluster were retained, and their correlation with PC loadings calculated. All PC loadings were included as potential independent variables and tested for significance using backward stepwise regression. The PC loadings with a correlation |≥0.49| explained significant variation in each trait and were included in the final models chosen; adjusted r2 values for BW, FEC, and FAM were 0.90, 0.81, and 0.97, respectively. When analyzing GIN challenge, eco-management clusters corresponding with hotter temperatures and greater rainfall, and with pasture-born lambs, suffered greater parasitism. Conversely, the eco-management clusters with lambs turned out to pasture at older ages benefited from reduced parasitism. Through the formation of eco-management clusters, an environmental variable can be defined to study interactions of genotypes to their environment, providing a potentially useful tool for identifying parasite-resistant sheep
Leukotriene B4 stimulates the release of arachidonate in human neutrophils via the action of cytosolic phospholipase A2
AbstractLeukotriene B4 (LTB4) is a potent lipid mediator of inflammation and is involved in the receptor-mediated activation of a number of leukocyte responses including degranulation, superoxide formation, and chemotaxis. In the present research, stimulation of unprimed polymorphonuclear leukocytes (neutrophils) with LTB4 results in the transient release of arachidonate as measured by mass. This release of arachidonate was maximal at an LTB4 concentration of 50–75 nM and peaked at 45 s after stimulation with LTB4. The transient nature of this release can be attributed, in part, to a fast (<60 s) metabolism of the added LTB4. Moreover, the inhibition of the reacylation of the released arachidonate with thimerosal results in greater than 4-times as much arachidonate released. Thus, a rapid reacylation of the released arachidonate also contributes to the transient nature of its measured release. Multiple additions of LTB4, which would be expected to more closely resemble the situation in vivo where the cell may come into contact with an environment where LTB4 is in near constant supply, yielded a more sustained release of arachidonate. No release of [3H]arachidonate was observed when using [3H]arachidonate-labeled cells. This indicates that the release of arachidonate as measured by mass is most probably the result of hydrolysis of arachidonate-containing phosphatidylethanolamine within the cell since the radiolabeled arachidonate is almost exclusively incorporated into phosphatidylcholine and phosphatidylinositol pools under the non-equilibrium radiolabeling conditions used. Consistent with the role of cytosolic phospholipase A2 (cPLA2) in the release of arachidonate, potent inhibition of the LTB4-stimulated release was observed with methylarachidonylfluorophosphonate, an inhibitor of cPLA2 (IC50 of 1 μM). The bromoenol lactone of the calcium-independent phosphospholipase A2. failed to affect LTB4-stimulated release of arachidonate in these cells
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